Many people have nonfunctioning or malfunctioning natural sphincters which make it impossible for them to control the discharge of body wastes through body passages.
One of the most common troublesome and embarrassing such conditions is the malfunctioning of the urethral sphincter. Normally, the urethral sphincter is responsible for controlling the flow of urine from the bladder of a person. When the urethral sphincter is malfunctioning the flow of urine from the bladder cannot be controlled. Obviously, this can be embarrassing to an individual and restrict his activities. A similar problem exists where the rectal sphincter fails to function properly.
A number of attempts have been made in the past to provide artificial sphincters which can substitute for a malfunctioning natural sphincter, or to control an artificially created body passage which has no natural sphincter.
The earliest artifical sphincters were external devices. However, in recent years, artificial sphincters have been developed which are implanted within the abdominal cavity of the patient. One example of such an implantable aritifical sphincter is that disclosed in the Reinicke U.S. Pat. No. 4,167,952. The sphincter disclosed in the Reinicke patent is a hydraulic system which includes a normally inflated cuff for encircling the urethra, a control unit including a reservoir for inflating fluid and a valve for controlling the fluid pressure in the cuff to minimize tissue damage and tubing connecting the control unit to the cuff. The valve of the control unit can be manually opened by digital pressure to deflate the cuff and open the urethra. The cuff can be reinflated to close the urethra by exerting digital pressure on the reservoir of the control unit.
Recently, an implantable artifical sphincter system has been proposed which has a double chambered cuff in which one chamber of the cuff is maintained at a relatively constant static pressure and the other chamber of the cuff is inflated to collapse the vessel against the first chamber and deflated to permit the vessel to open. The chamber of the cuff which is maintained at a static pressure does not have to be inflated or deflated once its internal pressure has been established at the proper level. The other chamber of the cuff, which can be inflated and deflated, is a part of a hydraulic system, like that of Reinicke.
Implantable, artificial sphincters which have either a single chamber cuff such as that disclosed in the Reinicke patent or the recently proposed double chamber cuff require that the cuff be securely positioned about the vessel to be controlled. Generally, this has been done by tying or suturing the cuff in place. In addition to being time consuming, in some instances, securing the cuff in place in such a manner has interfered with the blood supply for the tissue of the wall passage, such as the colon, which is furnished by blood vessels in the mesentery connecting the body passage to the peritoneum. This has resulted in tissue necrosis requiring the removal or replacement of the artificial sphincter.